南半球各类图像自动更新暨非扰动云团专帖（2024年7月－2025年6月）

红豆棒冰冰

AWIO20 FMEE 091115
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 09/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a broad Near Equatorial Trough (NET) pattern undulating around 3°S, between 56°E and 80°E.
Convective activity is confined to the slowing trade winds to the east of the Seychelles archipelago, as well as to the
north of 12°S, to the immediate east of the Mozambican coast, in the mesoscale convergences.
The weak wet phase of the MJO that will continue to cross the basin over the next few days should struggle to express
itself, being inhibited by both a near-equatorial easterly wind anomaly due to the weakly positive IOD, adding to the
current anticyclonic phase of a Rossby wave. The NET should therefore continue to lack convergence and vorticity over
the next few days, limiting cyclogenesis potential in the short term.
Development of a tropical storm is not expected over the next 5 days.
Extended outlook (D+5/D+10) :
Over the coming week, the wet phase of the MJO should shift slowly towards the Indonesian region while gradually
weakening, overlapping with a powerful equatorial Rossby wave, which should enhance vorticity near the north-eastern
border of our basin in the second part of the week (from around May 15th onwards). Some members of the EPS and
GEFS ensembles suggest the formation of a tropical low that could develop into a tropical storm in a few scenarios,
either in the Indonesian area or over the north-eastern corner of our basin. We'll thus be keeping a close eye on this
potential.

红豆棒冰冰

AWIO20 FMEE 101049
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 10/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a broad Near Equatorial Trough (NET) pattern undulating around 3°S, between 56°E and 80°E.
Convective activity is confined to the slowing trade winds to the east of the south ot th NET as well as to the north of
12°S, to the immediate east of the Mozambican coast, in the mesoscale convergences.
The weak wet phase of the MJO that will continue to cross the basin over the next few days should struggle to express
itself, being inhibited by both a near-equatorial easterly wind anomaly due to the weakly positive IOD, adding to the
current anticyclonic phase of a Rossby wave. The NET should therefore continue to lack convergence and vorticity over
the next few days, limiting cyclogenesis potential in the short term.
Development of a tropical storm is not expected over the next 5 days.

---

AWIO20 FMEE 101050
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 10/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a broad Near Equatorial Trough (NET) pattern undulating around 3°S, between 56°E and 80°E.
Convective activity is confined to the slowing trade winds to the south of the NET as well as to the north of 12°S, to the
immediate east of the Mozambican coast, in the mesoscale convergences.
The weak wet phase of the MJO that will continue to cross the basin over the next few days should struggle to express
itself, being inhibited by both a near-equatorial easterly wind anomaly due to the weakly positive IOD, adding to the
current anticyclonic phase of a Rossby wave. The NET should therefore continue to lack convergence and vorticity over
the next few days, limiting cyclogenesis potential in the short term.
Development of a tropical storm is not expected over the next 5 days.

红豆棒冰冰

红豆棒冰冰 发表于 2025-5-9 23:00
ECMWF系集持续对南太有所反应

从左到右三个系统分别已编号93P、94P、95P

红豆棒冰冰

AWIO20 FMEE 111105
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 11/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a broad Near Equatorial Trough (NET) pattern undulating around 3°S, between 60°E and 90°E.
Convective activity is confined to the slowing trade winds to the south of the NET as well as off the Tanzanian coasts.
The weak wet phase of the MJO that will continue to cross the basin over the next few days should struggle to express
itself, being inhibited by both a near-equatorial easterly wind anomaly due to the weakly positive IOD, adding to the
current anticyclonic phase of a Rossby wave. The NET should therefore continue to lack convergence and vorticity over
the next few days, limiting cyclogenesis potential in the short term.
Development of a tropical storm is not expected over the next 5 days.
The intersection of a Rossby wave with the end of the wet phase of the MJO may temporarily gather a bit more
favourable conditions in the north-east corner of the basin over the end of next week.

红豆棒冰冰

AWIO20 FMEE 121134
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 12/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a broad Near Equatorial Trough (NET) pattern undulating around 3-4°S east of 60°E, associated with
moderate convective activity. Convection is also still ongoing near the Tanzanian coast.
Within a weak wet phase of the MJO currently over the east of the basin, a Kelvin wave circulating around 14-15 May is
expected to cross a Rossby wave, which will temporarily enhance equatorial westerlies and vorticity within the NET
between the north-east of our basin and the Indonesian region over the next few days.
However, the effect of this wave activity should be partially inhibited by an equatorial easterly wind anomaly linked to the
weakly positive IOD. In addition, the equatorial westerlies seem to be converging more towards the northern hemisphere
and therefore less efficiently towards our basin, in line with the approaching southern-hemispheric winter.
The NET should therefore continue to lack convergence and vorticity over the next few days, limiting cyclogenesis
potential in the short term. Some very rare members of the EPS and GEFS ensembles forecast the development of a
tropical low at the end of the week, but this option seems very unlikely.
Development of a tropical storm is not expected over the next 5 days.
Beyond D+5, vorticity associated with the Rossby wave could persist over the north-east of the basin while moving
slowly westwards, although doing so within an increasingly unfavorable large-scale background.

红豆棒冰冰

AWIO20 FMEE 131049
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 13/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a broad Near Equatorial Trough (NET) pattern undulating around 2-6°S east of 56°E, associated with
moderate convective activity. Convection is also still ongoing near the Kenyan coast.
Within a weak wet phase of the MJO currently over the east of the basin, a Kelvin wave circulating around 14-15 May is
expected to cross a Rossby wave, which will temporarily enhance equatorial westerlies and vorticity within the NET
between the north-east of our basin and the Indonesian region over the next few days. This equatorial westerlies seems
to be converging more towards the northern hemisphere and therefore less efficiently towards our basin, in line with the
approaching southern-hemispheric winter. In addition, an equatorial easterly wind anomaly linked to the weakly positive
IOD is inhibiting attempts at cyclogenesis in our basin.
The NET should therefore continue to lack convergence and vorticity over the next few days, limiting cyclogenesis
potential in the short term. Some very rare members of the EPS and GEFS ensembles forecast the development of a
tropical low at the end of the week, but this option seems very unlikely.
Development of a tropical storm is not expected over the next 5 days.
Beyond D+5, vorticity associated with the Rossby wave could persist over the north-east of the basin while moving
slowly westwards, although doing so within an increasingly unfavorable large-scale background.

红豆棒冰冰

AWIO20 FMEE 141144
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 14/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a broad Near Equatorial Trough (NET) pattern undulating around 2-6°S east of 68°E, associated with
moderate convective activity.
Within a weak wet phase of the MJO currently over the east of the basin, a Kelvin wave currently on its way eastwards
up to tomorrow and crossing a Rossby wave, will temporarily enhance equatorial westerlies and vorticity within the NET
between the north-east of our basin and the Indonesian region over the next few days. This equatorial westerlies seems
to be converging more towards the northern hemisphere and therefore less efficiently towards our basin, in line with the
approaching southern-hemispheric winter. In addition, an equatorial easterly wind anomaly linked to the weakly positive
IOD is inhibiting attempts at cyclogenesis in our basin. The MJO return to the negative phase this weekend will also
contribute in this way.
Development of a tropical storm is not expected over the next 5 days.
Beyond D+5, vorticity associated with the Rossby wave could persist over the north-east of the basin while moving
slowly westwards, although doing so within an increasingly unfavorable large-scale background.

红豆棒冰冰

AWIO20 FMEE 151046
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 15/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a Near Equatorial Trough (NET) pattern to the east of the Seychelles archipelago, undulating between
2 and 6°S. Convective activity is low except at near equatorial latitudes, at the northern edge of this NET, in the bend of
the trade winds flow.
Our basin is now entering into the dry phase of the MJO, which is shifting further into the Australian AoR. The Kelvin
wave mentioned yesterday has also moved into the southeastern Indian Ocean basin, at near-equatorial latitudes, and is
completing its interaction with an equatorial Rossby wave. The latter not only favors the establishment of westerly
equatorial winds but also stabilizes the Near Equatorial Trough (NET) structure over the eastern part of our basin, while
developing (in the Indonesian zone) low-level vorticity.
This equatorial westerly flow seems to be diverging towards the northern hemisphere as the days go by, gradually
destructuring the current NET, in line with the onset of the austral winter. In addition, an equatorial easterly wind
anomaly linked to the weakly positive IOD is inhibiting attempts at cyclogenesis in our basin.
Development of a tropical storm is not expected over the next 5 days.
Beyond D+5, vorticity associated with the Rossby wave could persist over the north-east of the basin while moving
slowly westwards, although doing so within an increasingly unfavorable large-scale background.

红豆棒冰冰

AWIO20 FMEE 161058
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 16/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin features a Near Equatorial Trough (NET) pattern to the east of the Seychelles archipelago, undulating between
2 and 6°S. Convective activity is low except in the extreme northeast of the basin, where a zone of vorticity remains.
Our basin is now in the dry phase of the MJO,. An equatorial Rossby wave not only favors the establishment of westerly
equatorial winds but also stabilizes the Near Equatorial Trough (NET) structure over the eastern part of our basin, while
developing (in the Indonesian zone) low-level vorticity.
This equatorial westerly flow seems to be diverging towards the northern hemisphere as the days go by, gradually
destructuring the current NET, in line with the onset of the austral winter. In addition, an equatorial easterly wind
anomaly linked to the weakly positive IOD is inhibiting attempts at cyclogenesis in our basin.
Development of a tropical storm is not expected over the next 5 days.
Beyond D+5, vorticity associated with the Rossby wave could persist over the north-east of the basin while moving
slowly westwards, although doing so within an increasingly unfavorable large-scale background.

红豆棒冰冰

AWIO20 FMEE 171051
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE
BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN
DATE: 17/05/2025 AT 1200 UTC
PART 1: WARNING SUMMARY
Nil.
PART 2 : TROPICAL WEATHER DISCUSSION
The basin remains in a Near Equatorial Trough (NET) configuration to the east of 60°E, undulating between 2 and 7°S.
Convective activity is weak to almost non-existent, and is located to the east of a circulation present at the eastern edge
of our basin, towards 95°E.
The wet phase of the MJO is located to the east of our basin, leaving our basin predominantly dry. This unfavorable
context continues, although an equatorial Rossby wave could allow a weak low-pressure circulation to develop over the
eastern part of the basin. However, conditions remain unfavorable for a more significant development of vorticity.
Development of a tropical storm is not expected over the next 5 days.
Beyond D+5, the vorticity associated with the Rossby wave could persist over the northeast of the basin over the course
of next week, while moving slowly westwards, but in a large-scale context that remains hostile to any more significant
development.